diff --git a/jet/main.py b/jet/main.py
index 2c0515a..f017d37 100644
--- a/jet/main.py
+++ b/jet/main.py
@@ -120,9 +120,14 @@ def main():
         else:
             log.info("Checksum for file %s. %s %s:", destination, sha_bits, sha)
 
+        if f["mode"] is not None:
+            fmode = f["mode"]
+        else:
+            fmode = f"{os.stat(destination).st_mode&0o777:03o}"
+
         content_manifest += "%s %s=%s uid=%s gid=%s mode=%s program_id=%s\n" % \
             (f["destination"][1:] if f["destination"][0] == "/" else f["destination"],
-            sha_bits, sha, f["uid"], f["gid"], f["mode"], f["program_id"])
+            sha_bits, sha, f["uid"], f["gid"], fmode, f["program_id"])
 
         if f["symlink"]:
             contents_symlink += "%s%s %s\n" % (mount_dir, f["destination"], f["destination"])
diff --git a/jet/utils.py b/jet/utils.py
index 61cb9b1..e7f49fb 100644
--- a/jet/utils.py
+++ b/jet/utils.py
@@ -138,7 +138,7 @@ def required(d, k):
             "destination": required(file, "destination"),
             "uid": file.get("uid", 0),
             "gid": file.get("gid", 0),
-            "mode": file.get("mode", 555),
+            "mode": file.get("mode", None),
             "program_id": file.get("program_id", 1),
             "symlink": file.get("symlink", True),
         })